Aqua Traiana

The Aqua Traiana was a 1st-century Roman aqueduct built by Emperor Trajan and inaugurated on 24 June 109 AD. It channelled water from sources around Lake Bracciano, 40 kilometers north-west of Rome, to Rome in ancient Roman times but had fallen into disuse by the 17th century. It fed a number of water mills on the Janiculum, including a sophisticated mill complex revealed by excavations in the 1990s under the present American Academy in Rome. Some of the Janiculum mills were famously put out of action by the Ostrogoths when they cut the aqueduct in 537 during the first siege of Rome. Belisarius restored the supply of grain by using mills floating in the Tiber. The complex of mills bears parallels with a similar complex at Barbegal in southern Gaul.